1. Field of the Invention
The present invention relates to a device for detecting the amount of liquid in a vessel. The device according to the present invention is used, for example, for detecting the amount of fuel in a fuel tank provided in an automobile.
2. Description of the Prior Art
In a known device for detecting the amount of liquid in a vessel, a float is provided to float on the surface of the liquid, a contact is fixed to the float, and a resistor is provided to work with the contact. The contact slides on the resistor in accordance with the movement of the float due to the change in the level of the liquid. Hence, the amount of the liquid is detected by the change of resistance between the contact and one end of the resistor.
It is difficult to correctly detect an amount of liquid by such a device, however, because of differences between the shape of the vessel and the shape of the surface of the resistor, differences in resistance due to the contact area between the contact and the resistor, and volumetric expansion of the liquid due to temperature changes.
In this regard, there has long been a demand for a device which can correctly detect the amount of fuel in the fuel tank of an automobile, where there is the additional problem of vibration. No satisfactory device has yet been developed.